Go to Appearance > Customize > WooCommerce > Single Product Setting.
Up Sell Product – These are the items that your customer might prefer instead of the product currently viewed. Items which is offered as an up-sell might be more popular, have better profit margin or a higher quality.
Check the box “Display upsell product”. If you check this box you can now set the Number of Column and Number of up-selling Product you want to show.
To setup Up sell Product, Go to WooCommerce > Products and select the product on which you’d like to show in Up-sell. Scroll down to the Product Data panel. Select the Linked Products tab in the left menu. Add the product you wish to link to by searching for it.
